Pile driving and drawing apparatus

ABSTRACT

A pile driving and drawing apparatus for use in foundation works, provided with a weight assembly which houses an excitor, and resilient bodies, two of which are interposed between the weight assembly and the head of a pile, another being interposed between said weight assembly and means for suspending the same. The frequency of the excitor is so designed as to coincide with the frequency of the weight assembly, the latter being dependent on one of said resilient bodies interposed between the weight assembly and the pile head, whereby the vibration of the weight assembly imparts downward driving forces to the pile head. The frequency of the excitor is also designed to coincide with the frequency of the weight assembly, the latter frequency being dependent on the other of said resilient bodies interposed between the weight assembly and the pile head as well as the resilient body interposed between said weight assembly and said suspending means, whereby the vibration of the weight assembly imparts upward driving forces to the pile for the drawal thereof.

[ Nov. 18, 1975 PILE DRIVING AND DRAWING APPARATUS Hiroomi Makita,Tokyo, Japan Toyoda Kikai Kogyo Kabushiki Kaisha, Shizuoka, Japan Filed:May 3, 1974 Appl. N6; 466,675

Inventor:

Assignee:

[56] References Cited UNITED STATES PATENTS ll/l961 Berthet et a1.

6/1968 Menard 3/1970 Herz 1/1974 FOREIGN PATENTS OR APPLICATIONS Bodine173/49 2,( )l9,620 11/1971 Germany .,173/9l Primary Examiner-Ernest R.Purser Attorney, Agent, or Firm-Bruce K. Thomas ABSTRACT A pile drivingand drawing apparatus for use in foundation works, provided with aweight assembly which houses an excitor, and resilient bodies, two ofwhich are interposed between the weight assembly and the head of a pile,another being interposed between said weight assembly and means forsuspending the same. The frequency of the excitor is so designed as tocoincide with the frequency of the weight assembly, the latter beingdependent on one of said resilient bodies interposed between the weightassembly and the pile head, whereby the vibration of the weight assemblyimparts downward driving forces to the pile head. The frequency of theexcitor is also designed to coincide with the frequency of the weightassembly, the latter frequency being dependent on the other of saidresilient bodies interposed between the weight assembly and the pilehead as well as the resilient body interposed between said weightassembly and said suspending means, whereby the vibration of the weightassembly imparts upward driving forces to the pile for the drawalthereof.

14 Claims, 16 Drawing Figures "U.S. Patent Nov. 18, 1975 Sheet 1 of63,920,083

F/Z/ H212 w. W Efi U.S. Patent Nov.18,1975 Sheet 2 of6 3,920,083

F/i/O Fig/Y US. Patent Nov. 18, 1975 sheen of6 3,920,083

Fig/2 Patent Nov. 18, 1975 Sheet 5 of6 3,920,083

US. Patent Nov. 18,1975 Sheet60f6 3,920,083

FILE DRIVING AND DRAWING APPARATUS This invention relates to a piledriving and drawing apparatus for driving and drawing a pile for use infoundation works, which pile is made of concrete, steel or wood andprovided in a pole, tubular or sheet form.

Hitherto, known as apparatuses or devices for driving piles for use infoundation works into the ground are a drophammer, diesel hammer, steamhammer, etc. However, those apparatuses or devices only provide drivingcycles ranging from 5 to 200 blows/min. On the other hand, a vibrationtype pile hammer, one of the conventional apparatuses, has at least apair of weights and utilizes centrifugal forces created thereby, whileit provides driving cycles of over 1,000 blows/min. This apparatus,however, dictates the use of an extremely great driving force utilizingthe centrifugal force of a pair of weights for directly exerting thehead of a pile, with said weights being moved in a vertical direction insynchronism with each other. This in turn results in damages on the pilehead, in case the pile is made of a concrete having lower tensilestrength.

The present invention is directed to avoiding the drawbacks experiencedwith the prior art pile driving apparatuses.

According to the one aspect of the present invention, there is providedan apparatus adapted to drive a pile into the ground, comprising a guidemember having an I shaped cross section and consisting of a rod havingflanges, one of which is to be positioned on the head of a pile to bedriven into the ground; a weight assembly relatively moving with respectto said guide member, said assembly including a casing having animpinging portion adapted to impinge on one of said flanges .of saidguide member and a bore portion adapted to slideably receive the rod ofsaid guide member therein, said bore portion being located centrally ofsaid casing and said impinging portion being positioned at the lower endof said bore portion, and an excitor housed in said casing; and aresilient body interposed between one of said flanges and said impingingportion of said casing, the frequency of said excitor being incoincidence with that of said weight assembly, which is dependent onsaid resilient body.

According to another aspect of'the present invention, there is providedan apparatus adapted to draw a pile from the ground, comprising a guidemember of an I shaped cross section and consisting of a rod havingflanges, one of which'is to be secured to the head of a pile; a weightassembly relatively moving with respect to said guide member, saidassembly including a casing having a bore portion adapted to slidinglyreceive said rod and an impinging portion adapted to impinge on one ofsaid flanges and positioned at the upper end of said bore portion, andan excitor housed in said casing; a first resilient body interposedbetween the top of said weight assembly and supporting means forsuspending said weight assembly; and a second resilient body interposedbetween one of said flanges and said impinging portion of said casing,the frequency of said excitor being in coincidence with that of theweight assembly which is dependent on said first and second resilientbodies.

Before proceeding with the description of the preferred embodiments ofthe invention, it would aid in better understanding of the presentinvention to de- 2 scribe the. two fundamental principles incorporatedin the present invention. The first principle of the present invention:

Referring .to FIG. 1, suppose that a weight W is dropped on a springfrom a height h above the spring having a free length H and a springconstant k, and thereby the spring is compressed a distance y acting aforce F on a floor, after which the weight W is bounced upwards by meansof a restoring force of the spring to its initial position. If a dampingforce is not present, such upward and downward movements of a springwill be continued permanently, effecting free vibration having afrequencyf.

In this case, the following formula will be maintained among thosefactors such as the weight W of a weight, l

frequencyf, total amplitude A h, y spring constant k, impact F acting ona floor and acceleration coefficient F/W): spring energy y l I a My T yothen, according to the principle of the conservation of energy,

Suppose that the time required for a weight to effect the free drop fromor bouncing upwards to a height h,

from formula,

The equation of motion during the movement of a weight in contact withthe spring will be given as follows:

Sln W I This represents simple harmonic oscillation having a vibrationcenter of time having the vibration center given as the time originalpoint.

Suppose that t represents the time required for movlng up or downbetween the vibration center H and the When the above formula issubstituted by y W/k) from formula (I),

Suppose that T and frepresent total period of vibration and frequency,respectively, then From formulae (3). (5) and (6),

The total amplitude A will be given as follows:

From formula (7),

If the acceleration coefficient F/W) and f are given, then the totalamplitude A will be determined from formula (8), while the compressedamount ofthe spring will be also determined from formula (9).

On the other hand, if the acceleration coefficient 5, frequency f andweight of a weight W are given, the required spring constant k will bedetermined from formula (7).

If the free vibration of the weight overcomes a damping force which isinevitably present, to allow the permanent vibration, while an excitoris housed within the weight so as impart continuous vibration ordownward impact F of the head of a pile, with the frequency of theexcitor being in coincidence with the free frequency f of the weight,then there will arise a resonance phenomenon therebetween, whereby thedrive house power of the excitor will be converted into the work ofdriving a pile into the ground at the maximum efficiency.

FIG. 2 shows a centrifugal weight type excitor having two weightsadapted to rotate in opposite directions to each other at a frequency f,thereby producing vibration in a vertical direction. The weight of twoweights (2w) and the additional weight accompanied therewith are assumedas being included in the weight of a weight W.

The maximum exciting force q in the vertical direction in this case isgiven as follows:

The following prerequisites should be satisfied for starting to move theweight w.

As is apparent from formula (2), the weight w of rotary weights of theexcitor is extremely small, as compared with that of the weight W ofweight.

The horse power P required for driving the excitor will be given asfollows, with the proviso that A represents the total amplitude of therotary weights:

wardly and the magnitude thereof will be as follows:

mwr cos X 2, whereas 0 on wherein t represents the time origin when therotary weights having mass m is positioned at the uppermost position.

Accordingly, the centrifugal force is 2mw r cos wt. When the excitorhaving a weight W vibrates at the total amplitude A or at the halfamplitude A/2, and the Accordingly, the work of the excitor during thetime dt will be given as follows:

w cos mt'dt (2mw r) cos and! 2mw r cos an 2 The work of the excitorduring one rotation will be as follows, with the proviso that the periodAssume the frequency of f, then the work done during a unit time will beftimes as much as the work. If this is assumed as being power P, thenwhereas q 2mw r is the maximum centrifugal force of the excitor,

Further assume that the weight of one rotary weight is Referring to FIG.4, if a pile S is driven into the ground at the same frequency as thatof the weight having a weight W, yet at the total amplitude A, theapparent amplitude of the weight will be 2A. In other words, when thepile is not sinking, the weight will vibrate at the total amplitude A ina condition (a), while if the pile is sinking, the weight will vibratein conditions (b) and (c), and thus the total amplitude will be 2 A. Thehorse power Pmax in this case will be as follows:

Pmax 2p As is apparent from the foregoing description, as shown in FIG.2, if a resilient body having a spring constant k is secured to a pileS, and a weight having weight W is housed in excitor, with the frequencyof said excitor being in coincidence with that of a weight which isdependent on said resilient body, then there will arise a resonance.Accordingly, the drive horse power of the excitor which may be estimatedfrom said Pmax will act on the pile as a driving force of a downwarddirection. The second principle of the present invention:

Referring now to FIG. 5, if a weight having weight is suspended by themedium of a resilient body having a spring constant k, by means of asupporting body A, and yet an object B is connected by the medium ofsaid resilient body having a spring constant k to said weight, and theweight is subjected to vertical vibration, then the weight will vibrateat a natural frequency f. Suppose that the weight effects downwardmovement, there will be created a clearance between the stationaryobject C and the object B, such that the object C will be located in aposition shown by the broken line. The weight will move downwardly untilthe aforesaid clearance reaches the maximum, after which the weightstarts moving upwards. While the weight is shifted to an upward movementand the object B contacts the object C, the weight will have maximumkinetic energy. The weight will undergo actions of the resilient bodyhaving spring constant k as well as the resilient body having a springconstant k,.

Accordingly, in case a weight assembly housing an excitor thereinconsisting of a pair of rotary weights and the vibration of a weight isso designed as to overcome a damping force for continuing vibration,then the object may exert an upward impact on the object C continuously.In addition, the maximum upward impact 7 exerted by the object B on theobject C will be achieved by bringing the frequency of said excitor incoincidence with the natural frequency of a weight which is dependent onsaid two resilient bodies, due to the resultant resonance.

Thus, this permits drawing of a pile by applying an upward force theretoby the medium of the object C integral with a pile. Alternatively, theobject C may be the pile itself.

The present invention thus presents a pile driving and/or drawingapparatus utilizing one or both of the aforesaid two principles.

These and other objects and features of the present invention will beapparent from a reading of the ensuing part of the specification, takenin connection with the drawings which indicate embodiments of thepresent invention, in which:

FIGS. 1 4 are diagrams illustrating the first principle of theinvention;

FIG. 5 is a diagram illustrating the second principle of the invention;

FIG. 6 is a side elevation of the pile driving and drawing apparatusaccording to the present invention, showing the supporting meanstogether;

FIG. 7 is a side elevation of the apparatus of the invention which isapplied to the drawing operation of a pile;

FIG. 8 is a longitudinal cross-sectional view of the apparatus accordingto the present invention;

FIGS. 9 and 10 are perspective views of a subsidiary eccentric weightassembly according to the present invention. showing the detailedconstruction thereof;

FIGS. 11 and 12 are longitudinal cross-sectional views of embodiments ofcaps each adapted to receive a pile head firmly, according to thepresent invention;

FIG. 13 is a longitudinal cross-sectional view of another embodiment ofthe apparatus according to the present invention;

FIG. 14 is a partial. longitudinal cross-sectional view taken along theline 14-14 of FIG. 13;

FIG. 15 is a partial, longitudinal cross-sectional view ofthe casing ofrollers shown in FIGS. 6, 7 and 8, showing the attachment thereof; and

FIG. 16 is a side elevation of an excitor housed in a casing.

Referring to FIG. 6, there is shown at 12 a pile driving and drawingapparatus according to the present invention, which is suspended by asupporting means 10. The supporting means 10 includes an endless trackvehicle l4 and a leader 16 pivotted thereto, and a boom 18 whoseopposite ends are pivotted to said vehicle and leader, and which isextensible.

The leader 16 is provided with a guide rod 20 disposed lengthwisethereof, with the top of said leader being provided with sheaves 22 and24. A wire is trained around sheaves 22 and 24 and a sheave 29 which isjournaled in a holder 28 having a hook 26.

The pile driving and drawing apparatus 12 includes a casing 32 whichhouses a plurality of rollers 34 engaging a guide rod 20 secured to theleader 16. The casing .32 is provided with a suspending ring 36 at thetop thereof, and the apparatus 12 is suspended by supporting means 10including wire by the medium ofa wire 38 of a ring form, which engagessaid suspending ring 36 and is adapted to receive the hook 26. Thecasing 32 is provided with a cap 42 in the lower portion thereof, whilethe cap 42 is adapted to fit on the head of a pile 44 which is to bedriven into the ground.

Referring to FIG. 7, the pile driving and drawing apparatus 12 hassuspending ring 36 and hook 26 connected to each other by the medium ofadamper 46 including a plurality of springs, while a chuck 48 is providedat the lower end of the casing. The chuck 48 secures the head of a sheetpile 50.

As can be seen from the foregoing, the pile driving and drawingapparatus according to the present invention is used either for drivinga pile as shown in FIG. 6 or for drawing a pile as shown in FIG. 7.

The construction of the pile driving and drawing apparatus 12 will bedescribed in more detail with reference to FIG. 8. As shown, the casing32 consists of an upper portion 32a housing a pair of rotors 54 therein(one of the rotors is shown in FIG. 8.) adapted to be driven and rotatedby means of an electric motor 52 and a lower portion 32b housing a guidemember 57 of an I shaped cross-section consisting of rods 56 having anupper flange 55a and a lower flange 55b. The pair of rotors 54 in theupper portion 32a of the casing are provided with gears 58 engaging eachother and an arcuate weight plates 60 attached to the outercircumference of the rotors 54 in an eccentric manner. The excitorconsists of said motor 52 and eccentric weights 60, and said rotors arerotated due to the operation of the motor 52. In this respect, thelateral and horizontal vibration will be off-set due to the rotation ofsaid eccentric weights, leaving a vertical vibration. During thenon-operating condition of the motor 52, each rotor maintains eccentricweights positioned still in its lower position as shown.

The lower portion 32b of the casing has an internal space defined so asto house said I shaped member 57 in a manner to permit the relativemovement thereof. The lower portion 32b of the casing includes a reducedportion 62 slidingly engaging the rod 56 of the I shaped member 57,upper shoulder portion 64 formed at the upper end of said reducedportion 62, and lower shoulder portion 66 at the lower end of thereduced portion 62.

The lower flange 55b of the rod 56 secures a cap 42 as shown in FIG. 6and a chuck 48 as shown in FIG. 7, depending on whether a pile is beingdriven or withdrawn. The casing and the excitor housed in the casingserve as weights which exert a driving force or drawing force to a pile.

The upper shoulder portion 64 and the lower shoulder portion 66 of thecasing 32 serve as impinging portions against the upper flange 55a andlower flange 55b of the I shaped member 57 the with respective flangesand shoulder portions have mounted thereon the resilient members 70, 72,74 and 76 made of rubber-like resilient material. The resilient members70 and 72 are interposed between the flange portion 55a and the shoulderportion 64 which are to impinge on each other upon drawing the pile. Thematerial and dimensions of the resilient members are designed to havesuch an elastic modulus such that the vibration frequency of theaforesaid weight assembly will coincide with the frequency of theexcitor which is dependent on said resilient bodies constituting adamper 46. On the other hand, the resilient bodies 74 and 76 areinterposed between the flange portion SSb and the shoulder portion 66,such that the material and dimensions of the aforesaid resilient bodiesare selected so as to have such an elastic modulus that renders thefrequency of the weight assembly, which is dependent on the resilientmembers, coincident with that frequency of the said excitor.

Upon driving a pile into the ground, the apparatus 12 is placed on thehead portion of the pile 44, as shown in FIG. 6, the weighted casing 32is adjusted by means of the cable suspension 30 in relation to the guidememher 57 so that only the lower shoulder 66 and the flange 55b willimpinge and then the motor 52 of the excitor is energized. This causesthe resonance between the excitor and the weight assembly, whereby adownward impact will be applied on the head of the pile. In other words,suppose that the acceleration coefficient if is constant C in formula(7), then If the elastic modulus of resilient bodies and the weight of aweight assembly are so selected as to render the value of W/g constant,then the impact may be obtained by setting the R.P.M. of the motor 52 tothe R.P.M. corresponding to the constant frequency fgiven thereby. Thedownward impact F exerted on the head of a pile by means of a weightassembly due to the resonance between the excitor and the weightassembly is extremely great, as compared with the horse power of themotor 52.

When comparing the drive horse power P of the apparatus according to thepresent invention with the drive horse power P of the conventionalvibrating type pile driver, the following relationship will be obtained:

From formula (12), P/P q/F a P e Although a l, a=2 4, 10 20 l P 10 EAccordingly, the same effect may be achieved with 10 to 40% horse powerof the conventional type pile driver. Even if is 10, the same effect maybe achieved with 20% horse power of the conventional vibration type piledriver, with some allowance being taken into consideration.

Next, upon drawing a pile from the ground, as shown in FIG. 7, the chuckis secured to the head of pile 50, and then said weight assembly, i.e.,the casing 12 housing the excitor therein is pulled upwards, to anextent that will not cause an initial tension in the pile. This placesthe weighted casing 32 in such a position relative to the guide member57 that when the excitor 54 is energized only the upper shoulder member64 and the upper flange 55a will impinge. Thus, when the weight assemblyis vibrated upwardly of the vibration center of the weight assembly, adrawing force may be effectively 10 applied to the pile. Thereafter, theexcitor is energized, causing the resonance between the frequency of theexcitor and the resilient members and the frequency of the weightassembly which is dependent on the resilient members 70, 72 and 46.However, when the weight assembly is lowered along the I shaped member57, it will not exert a downward force on the pile, but when the weightassembly is displaced upwardly, then the upper shoulder portion 64 ofthe casing 12 serving as weights will impinge on the upper flange 55a ofthe I shaped member 57 which is secured by the medium of chuck 48 to thepile head, thereby exerting an upward force or upward drawing force onthe pile head.

The resonance between the weight assembly and the excitor provides greatdrawing force at lower horse power to a pile while imparting vibrationto a pile, thereby reducing a friction force between the outer peripheryof the pile and the ground.

The weight of the weight assembly including the easing 32 and theexcitor housed in the casing 32 may be varied by removably attaching asuitable subsidiary weight to said weight assembly. It will beunderstood from the foregoing description that the variation in theweight of a weight assembly dictates the variation in R.P.M. of themotor 52 to insure said resonance. In addition, for insuring theconstant R.P.M. for the rotors 54 of the excitor, the subsidiaryeccentric weight 78 is attached to the respective rotors 54, as shown inFIG. 9, commensurate to the cycles of the motor electric power source.The eccentric weight, as shown, is made of a metallic material of ahalf-cylindrical shape, which is formed with two bent edge portions 80and 82, and fitted on the eccentric weights 60 on the rotors 54 insliding fashion, as shown in FIG. 10.

The edge portions 80 and 82 of the subsidiary weight 78 engage therespective edge portions 84 of the eccentric weights 60, therebypreventing the detachment thereof due to the rotation of the rotors.

While the I shaped guide member 57 as shown in FIG. 8 mounts cap 42 orchuck 48 for driving or drawing a pile, the typical embodiment of thecap will be described, in reference to FIGS. 11 and 12.

Shown in FIG. 11 is a cap 42 adapted to be fitted on the head of a pile44 to be driven into the ground. The cap 42 includes a top plate member86 bolted to the lower flange 55b of the I shaped member 57 and a sideplate which is integral with the top plate member 86 and of acylindrical form, said side plate having a plurality of openings in theperiphery thereof. Fixedly fitted by means of bolt-nut fastening means92 in the openings in the side plate are pile retaining assembliesextending in a radial direction of the cap. Furthermore, a guide ring94is secured by means of a bolt 96 to the inner side of the side platein the lower portion of the side plate 88, said guide ring 94 beingadapted to introduce the pile 44 into the cap 42. The pile retainingassemblies 90 consist of a plate member 100 having an extension 98received in said opening, a finger 104 fastened by means of bolt-nutassembly 102 to said plate member 100, and a coil spring 106, one end ofwhich is secured to the finger 104 and the other end of which is securedto the plate member 100. In this respect, the finger 104 is slidablealong the aforesaid extension in the radial direction of the cap, i.e.,the pile, depending on the diameter of the pile to be received in thecap 42. The finger 104 and guide ring 94 are formed with taperedsurfaces 107 and 108, thereby facilitating positioning and receipt of apile within the cap.

:For coping with the considerable degree of variation in the diameter ofthe pile. the working length of the boltnut assembly 102 may be variedor a suitable spacer may be inserted between the side plate 98 and theplate member 100 to thereby space the pile retaining assembly 90 fromthe axial line of the cap 42 in its entirety.

Referring to FIG. 12, the cap 42 fitted on the pile 50 made of a steelangle is rotatably journaled on the shaft I14 attached by the medium ofan attaching plate 112 to the base plate 110 which is bolted to thelower flange 55b of the I shaped member 57. Located within the bearingportion 116 of the cap 42 is a ball bearing 118 which surrounds theshaft 114. The ball bearing 118 is held in position by means of a ring122 held by the nut I20 fitted on said shaft 114.

The cap 42' is formed with a skirt portion 124 under the bearing portion116. while a pile retaining assembly 126 having a construction similarto that shown in FIG. 11 is provided for the skirt portion 124. The cap42' is rotatable about the shaft 114, with the pile being receivedwithin the skirt portion 124, such that the direction of the pile may bechanged as required at a given pile driving position.

Referring to FIGS. 8 and 13, the casing 32 constituting the weights ofthe pile driving and drawing apparatus 12 effects upward and downwardmovements relative to the guide member, i.e., the I shaped member 57,due to the operation of the excitor similarly forming weights. However,in this case, the casing 32 causes a lateral impact to the I shapedmember, in addition to the vertical impact thereon.

The magnitude of the lateral impact corresponds to about l% of thevertical impact.

Maximum vertical impact may be achieved by minimizing the lateralimpact. FIG. 13 shows an embodiment which is intended to reduce thelateral impact exerted by the weights on the guide member, i.e., the Ishaped member 57. A plurality of roller groups 130 are located adjacentto the flange portions 55a and 55b of the I shaped member in a spacedrelation along the circumference of the flanges, said roller groups 130being rotatable relative to the inner wall of the casing 32. Therespective roller groups include a plurality of rollers 131 as shown inFIG. 14. Respective rollers normally engage the edge faces 132 of therespective flanges, thereby permitting the smooth relative movement withrespect to the guide member of the weight assembly. The rollers are eachsupported by a shaft 138 by a axial support member 135 which is attachedby means of a plurality of bolt-nuts 136 to the flange 134 provided inthe lower portion 3212 (FIG. 8) of the casing 12. The re- :spectiverollers 131 are made of a rubber-like resilient material. In addition,the respective rollers have a configuration of a radius of curvatureequal to that of the flange 55a of the guide member. Disposed betweenthe flange 134 of the casing and the roller supporting member 136 are aspacer 140 and a damper 142 which are inserted in an attempt to vary therelative distance between the shaft 138 and the flange 55a. Dampingmembers of a material the same as that of said clamping member areattached to the attaching portions of the rollers 34 (FIGS. 6 to 8) tothe casing. In other words, as shown in FIG. 15, there are provideddamping members 152 and 154 between the base portions of the supportingshaft 146 of the rollers 34 and the outer side surface of casing 32 andbetween said base portion and the bracket 150 securing the base portionto the casing.

The bracket is secured by means of a plurality of bolts 156 to thecasing. Oil 158 is contained within the upper portion 32a (FIG. 8) ofthe casing which houses the motor 52 and the eccentric weight rotors 54driven by the motor 52, as shown in FIG. 16. The oil serves for theinsulating purpose for motor coils as well as for lubricating purposefor gears and motor bearing portions. The casing is provided with asuitable pressure adjusting means 160 to maintain the internal pressureconstant, because said oil will be atomized to a mist form due to therotation of the motor to thereby raise the pressure within the casing.After the stop of the motor, said oil 158 will drop through routes shownby arrows in FIG. 16 onto the lower portion of the upper portion 32a ofthe casing. More particularly, the oil which has been introduced by themedium of bearing 162 into a motor and the oil which has been introducedbetween the stator iron core 164 of the motor and the rotor iron core166 both drop through the openings 168 and 170 provided in the eccentricweights 60, and thus no oil dwells within the motor.

From the foregoing description it is apparent that in FIG. 8, the weightassembly is shown in a neutral position with respect to the guide member57. In driving a pile, the weight assembly is descended so that thelower shoulder portion 66 strikes only the lower flange portion 55b. Onthe contrary, in drawing a pile, the weight assembly is pulled upwardsso that the upper shoulder portion 64 strikes only the upper flangeportion 55a. These are operated by means of the wire 30 (FIG. 6).

The clearance between the shoulder portions and the flange portions isso designed that the clearance is sufficiently larger than the amplitudeof the weight assembly depending on the nature of the ground so that theupper shoulder portion 64 does not impinge on the upper flange portion55a in driving, and the lower shoulder portion 66 does not impinge onthe loweer flange portion 55b in drawing the pile. Generally, theamplitude of the weight assembly is mainly determined by the hardness ofthe ground in which a pile is driven by the action of the weightassembly. Accordingly, said clearance is selected in design to an extentwhich is sufficiently larger than that of rebound of the weight assemblyat the time of striking the pile into the hardest ground, whereby theweight assembly is not limited the amount of its vertical movement alongthe guide member 57 with anything and effectively exerts downward forcein driving and upward force in drawing on the pile, varying itsamplitude depending on the nature of the ground. This permits theapparatus to exert a relatively large force in striking the pile whenthe ground is hard and to exert a relatively small force when the groundis soft.

I claim:

1. A pile driving and drawing apparatus comprising a guide memberconsisting of a rod provided with a flange adapted to be placed on thehead of a pile to be driven into the ground;

a weight assembly adapted to effect the relative movement with respectto said guide member, said assembly including a casing provided with afirst portion for receiving the rod of said guide member in slidingengagement therewith and a second portion positioned below said firstportion and adapted to impinge on said flange, and said assembly furtherincluding an excitor provided within said casing; and

a resilient body placed between said flange and second portion of saidcasing,

the natural frequency of said excitor being so arranged as to coincidewith the free frequency of said weight assembly which is dependent onsaid resilient body.

2. A pile driving and drawing apparatus comprising a guide memberconsisting of a rod provided with one end adapted to be secured to thehead of a pile to be drawn from the ground and the other end having aflange;

a weight assembly effecting the relative movement with respect to saidguide member, said assembly including a casing provided with a firstportion for receiving the rod of said guide member in sliding engagementtherewith and a second portion positioned above said first portion andadapted to impinge on said flange, said assembly further including anexcitor provided within said casing;

a first resilient body interposed between said weight assembly and meansfor suspending said assembly; and

resilient second resilien body interposed between said flange and thesecond portion of said casing,

the natural frequency of said excitor being so arranged as to coincidewith the free frequency of said weight assembly which is dependent onsaid first and second resilient bodies.

3. A pile driving and drawing apparatus comprising:

a guide member adapted to be secured to the head of a pile andconsisting of a rod provided with upper and lower flanges;

a weight assembly effecting the relative movement with respect to saidguide member and including a casing provided with a bore portion adaptedto receive the rod of said guide member in sliding engagement therewithand upper and lower shoulder portions which are positioned on oppositesides'of said portion and adapted to impinge on said upper and lowerflanges, respectively, said assembly further including an excitor housedin said casing;

a first resilient body interposed between said weight assembly and meansfor suspending said assembly; and

second and third resilient bodies placed between said lower flange andthe lower shoulder portion of said casing and between said upper flangeand the upper shoulder portion of said casing, respectively;

the frequency of said excitor being so arranged as to coincide with thefrequency of said weight assembly which is dependent on said secondresilient body for driving a pile and the frequency of said excitorbeing so arranged as to coincide with the frequency of said weightassembly which is dependent on said first and third resilient bodies fordrawing a pile.

4. A pile driving and drawing apparatus according to claim 3, whereinsaid excitor includes a pair of electromotive rotors and respectiverotors are provided with weights positioned in eccentric fashion.

5. A pile driving and drawing apparatus according to claim 4, whereinsaid rotor is provided with a subsidiary eccentric weight removablyattached to said eccentric weight.

6. A pile driving and drawing apparatus according to claim 3, whereinsaid first resilient body consists of a coil spring assembly, and saidsecond and third resilient bodies are made of rubber-like resilientmaterials.

7. A pile driving and drawing apparatus according to claim 3, whereinsaid guide member is provided with a cap member of a cylindrical form atits lower end, said cap member having a plurality of spring biasedmembers placed in a spaced relation around the periphery of said capmember and extending in a radial direction of a pile to be receivedwithin said cap member.

8. A pile driving and drawing apparatus according to claim 3, whereinsaid guide member is provided with a cap member of a cylindrical formpivotally connected to the lower end thereof, said cap member beingprovided with at least one spring biased member extending in a directionperpendicular to the axis of a pile to be received within said capmember.

9. A pile driving and drawing apparatus according to claim 3, whereinsaid casing is provided with a plurality of rollers engaging the side ofthe flange of said guide member.

10. A pilev driving and drawing apparatus according to claim 3, whereinthe casing, which houses said excitor, contains oil adapted to becirculated within said casing during the operation of said excitor, andsaid excitor is provided with a pair of rotors and weights disposed ineccentric relation to said rotors, said weights being provided with aplurality of oil vents and said casing having means for adjusting thepressure within said casing.

11. A pile driving and drawing apparatus comprising:

a guide member adapted to be secured to the head of a pile;

a weight assembly movably mounted on said guide member to exert downwardor upward force on said pile, said weight assembly including an excitorcontained therein;

said guide member including a rod member provided with upper and lowerflanges;

said weight assembly defining a casing provided with a bore portionadapted to receive said rod member in sliding engagement therewith;

and upper and lower shoulder portions which are positioned on oppositeends of said bore portion and adapted to impinge on said upper flange inpile drawing and lower flange in pile driving, respectively;

a first resilient body for suspending said weight assembly;

second and third resilient bodies interposed between said lower flangeand the lower shoulder portions of said casing and between said upperflange and the upper shoulder portions of said casing, respectively;

the clearance between said flange portions and said shoulder portionsbeing larger than the amplitude of the weight assembly at the time itdrives the pile into the hardest ground, and the frequency of saidexcitor being adapted to coincide with the frequency of said weightassembly which is dependent on said second resilient body for driving apile and the frequency of said excitor, also being adapted to coincidewith the frequency of said weight assembly which is dependent on saidfirst and third resilient bodies for drawing a pile.

12. A pile driving and drawing apparatus comprising:

suspension means to hold a first resilient body;

a weight assembly attached to and suspended from said first resilientbody;

said weight assembly defining a casing and having an excitor operativelyconnected thereto;

said casing having upper and lower compartments with a central borecommunicating between said compartments;

said upper compartment having an upwardly facing shoulder about saidcentral bore and including a second resilient body thereabout;

said lower compartment having a downwardly facing shoulder about saidcentral bore and including a third resilient body thereabove;

a guide member within said casing;

said guide member having an upper flange member received in spacedrelationship within said upper compartment, an integral rod portionextending in guided relationship through said central bore and a lowerflange member received in spaced relationship within said lowercompartment;

said upper flange member being opposed to said second resilient body andsaid lower flange member being opposed to said third resilient body;

the axial length of said rod portion of said guide member being longerthan said central bore to define a clearance between said flangeportions and said shoulders; said respective flange portions beingengageable with said second and third resilient bodies; and

means to connect said lower flange portion of said guide member to apile;

the clearance between said flange portions and said shoulder portionsbeing larger than the amplitude 16 of the weight assembly at the time itdrives the pile into the hardest ground, and the frequency of saidexcitor being adapted to coincide with the frequency of said weightassembly which is dependent on said second resilient body for driving apile and the frequency of said excitor, also being adapted to coincidewith the frequency of said weight assembly which is dependent on saidfirst and third resilient bodies for drawing a pile. 13. A pile drivingand drawing apparatus in accordance with claim 12 wherein:

said casing is provided with a pair of opposing side openingscommunicating on opposite sides thereof with said upper and lowerflanges of said guide member; means supporting a plurality of rollers ineach of said side openings on axes within the plane of said flangeswhereby the inner peripheries of each plurality of rollers areengageable with the edges of said flanges; and dampening means areprovided holding said roller supporting means and rollers in saidperipheral engagement. 14. A pile driving and drawing apparatus inaccordance with claim 12 wherein:

said second and third resilient bodies each comprise opposing pads ofrubber-like material affixed to said respective flange members and saidshoulders.

1. A pile driving and drawing apparatus comprising a guide memberconsisting of a rod provided with a flange adapted to be placed on thehead of a pile to be driven into the ground; a weight assembly adaptedto effect the relative movement with respect to said guide member, saidassembly including a casing provided with a first portion for receivingthe rod of said guide member in sliding engagement therewith and asecond portion positioned below said first portion and adapted toimpinge on said flange, and said assembly further including an excitorprovided within said casing; and a resilient body placed between saidflange and second portion of said casing, the natural frequency of saidexcitor being so arranged as to coincide with the free frequency of saidweight assembly which is dependent on said resilient body.
 2. A piledriving and drawing apparatus comprising a guide member consisting of arod provided with one end adapted to be secured to the head of a pile tobe drawn from the ground and the other end having a flange; a weightassembly effecting the relative movement with respect to said guidemember, said assembly including a casing provided with a first portionfor receiving the rod of said guide member in sliding engagementtherewith and a second portion positioned above said first portion andadapted to impinge on said flange, said assembly further including anexcitor provided within said casing; a first resilient body interposedbetween said weight assembly and means for suspending said assembly; andresilient second resilien body interposed between said flange and thesecond portion of said casing, the natural frequency of said excitorbeing so arranged as to coincide with the free frequency of said weightassembly which is dependent on said first and second resilient bodies.3. A pile driving and drawing apparatus comprising: a guide memberadapted to be secured to the head of a pile and consisting of a rodprovided with upper and lower flanges; a weight assembly effecting therelative movement with respect to said guide member and including acasing provided with a bore portion adapted to receive the rod of saidguide member in sliding engagement therewith and upper and lowershoulder portions which are positioned on opposite sides of said portionand adapted to impinge on said upper and lower flanges, respectively,said assembly further including an excitor housed in said casing; afirst resilient body interposed between said weight assembly and meansfor suspending said assembly; and second and third resilient bodiesplaced between said lower flange and the lower shoulder portion of saidcasing and between said upper flanGe and the upper shoulder portion ofsaid casing, respectively; the frequency of said excitor being soarranged as to coincide with the frequency of said weight assembly whichis dependent on said second resilient body for driving a pile and thefrequency of said excitor being so arranged as to coincide with thefrequency of said weight assembly which is dependent on said first andthird resilient bodies for drawing a pile.
 4. A pile driving and drawingapparatus according to claim 3, wherein said excitor includes a pair ofelectromotive rotors and respective rotors are provided with weightspositioned in eccentric fashion.
 5. A pile driving and drawing apparatusaccording to claim 4, wherein said rotor is provided with a subsidiaryeccentric weight removably attached to said eccentric weight.
 6. A piledriving and drawing apparatus according to claim 3, wherein said firstresilient body consists of a coil spring assembly, and said second andthird resilient bodies are made of rubber-like resilient materials.
 7. Apile driving and drawing apparatus according to claim 3, wherein saidguide member is provided with a cap member of a cylindrical form at itslower end, said cap member having a plurality of spring biased membersplaced in a spaced relation around the periphery of said cap member andextending in a radial direction of a pile to be received within said capmember.
 8. A pile driving and drawing apparatus according to claim 3,wherein said guide member is provided with a cap member of a cylindricalform pivotally connected to the lower end thereof, said cap member beingprovided with at least one spring biased member extending in a directionperpendicular to the axis of a pile to be received within said capmember.
 9. A pile driving and drawing apparatus according to claim 3,wherein said casing is provided with a plurality of rollers engaging theside of the flange of said guide member.
 10. A pile driving and drawingapparatus according to claim 3, wherein the casing, which houses saidexcitor, contains oil adapted to be circulated within said casing duringthe operation of said excitor, and said excitor is provided with a pairof rotors and weights disposed in eccentric relation to said rotors,said weights being provided with a plurality of oil vents and saidcasing having means for adjusting the pressure within said casing.
 11. Apile driving and drawing apparatus comprising: a guide member adapted tobe secured to the head of a pile; a weight assembly movably mounted onsaid guide member to exert downward or upward force on said pile, saidweight assembly including an excitor contained therein; said guidemember including a rod member provided with upper and lower flanges;said weight assembly defining a casing provided with a bore portionadapted to receive said rod member in sliding engagement therewith; andupper and lower shoulder portions which are positioned on opposite endsof said bore portion and adapted to impinge on said upper flange in piledrawing and lower flange in pile driving, respectively; a firstresilient body for suspending said weight assembly; second and thirdresilient bodies interposed between said lower flange and the lowershoulder portions of said casing and between said upper flange and theupper shoulder portions of said casing, respectively; the clearancebetween said flange portions and said shoulder portions being largerthan the amplitude of the weight assembly at the time it drives the pileinto the hardest ground, and the frequency of said excitor being adaptedto coincide with the frequency of said weight assembly which isdependent on said second resilient body for driving a pile and thefrequency of said excitor, also being adapted to coincide with thefrequency of said weight assembly which is dependent on said first andthird resilient bodies for drawing a pile.
 12. A pile driving anddrawing apparatus comprising: suspension means to hold a first resilientbody; a weight assembly attached to and suspended from said firstresilient body; said weight assembly defining a casing and having anexcitor operatively connected thereto; said casing having upper andlower compartments with a central bore communicating between saidcompartments; said upper compartment having an upwardly facing shoulderabout said central bore and including a second resilient bodythereabout; said lower compartment having a downwardly facing shoulderabout said central bore and including a third resilient body thereabove;a guide member within said casing; said guide member having an upperflange member received in spaced relationship within said uppercompartment, an integral rod portion extending in guided relationshipthrough said central bore and a lower flange member received in spacedrelationship within said lower compartment; said upper flange memberbeing opposed to said second resilient body and said lower flange memberbeing opposed to said third resilient body; the axial length of said rodportion of said guide member being longer than said central bore todefine a clearance between said flange portions and said shoulders; saidrespective flange portions being engageable with said second and thirdresilient bodies; and means to connect said lower flange portion of saidguide member to a pile; the clearance between said flange portions andsaid shoulder portions being larger than the amplitude of the weightassembly at the time it drives the pile into the hardest ground, and thefrequency of said excitor being adapted to coincide with the frequencyof said weight assembly which is dependent on said second resilient bodyfor driving a pile and the frequency of said excitor, also being adaptedto coincide with the frequency of said weight assembly which isdependent on said first and third resilient bodies for drawing a pile.13. A pile driving and drawing apparatus in accordance with claim 12wherein: said casing is provided with a pair of opposing side openingscommunicating on opposite sides thereof with said upper and lowerflanges of said guide member; means supporting a plurality of rollers ineach of said side openings on axes within the plane of said flangeswhereby the inner peripheries of each plurality of rollers areengageable with the edges of said flanges; and dampening means areprovided holding said roller supporting means and rollers in saidperipheral engagement.
 14. A pile driving and drawing apparatus inaccordance with claim 12 wherein: said second and third resilient bodieseach comprise opposing pads of rubber-like material affixed to saidrespective flange members and said shoulders.